1. Field of the Invention
The present invention relates to security closure and latching devices and more particularly relates to a novel security latch which permits or allows selective opening, restricted opening and closed positions of a door of means of a novel closure element and latch member combination.
2. Description of the Prior Art
In the past, a variety of door latching devices have been employed for permitting a door to be opened and closed at the direction of a person within a house or room. One such prior device takes the form of a chain secured at one end to the door jamb and selectively secured at its opposite end to a shaped notch carried on a securement member fixed to the door. The operator may readily move the chain from the element secured to the door at will when it is desired to fully open the door. When the chain is affixed to the element, a restricted opening of the door is permitted so that unwanted intruders can be identified through the restricted opening between the door edge and the door jamb and still the door is prevented from opening. However, once the chain has been removed from its selected attachment with the door element, the device is inoperative and cannot prevent or restrict the door from opening. The device requires a positive detachment of the chain from the door element which requires additional positioning of the door so as to permit sufficient slack in the chain to allow the removal of the chain end from the door element. Therefore, the device is cumbersome, awkward and limited in its application as a security latch.
Other attempts have been made to provide an adequate security latch which involve rigid bolts having finger actuating elements which are positioned into respective notches arranged along the edge of a longitudinal slot. Such devices do not provide for restricted or limited opening of the door and are usually limited to either fully locking the door to the door jamb or fully opening the door for unrestricted use.
Therefore, a need has long existed to provide a novel latching mechanism which provides for restricted opening of the door and which will permit the door to be selectively opened when desired as well as closed.